Evaluation and Reporting on Contaminant Hydrogeological

12-12-01

Conditions at the Tajiguas Landfill

Page 3 of 24

I

NTRODUCTION

Tajiguas Landfill was opened by Santa Barbara County in 1967 as a Class III solid

waste disposal site. Small volumes of waste had been unofficially dumped on the

canyon floor even before the site came under County control. Does not appear to be

any record for any removal of alluvium. During the initial period of County operation,

land filling took place along both banks of the Canada de la Pila streambed, from

which flow had not been diverted. Waste was then placed in the streambed,

damming off runoff from the upper watershed. Currently the landfill is permitted to

receive 1,500 tons per day of municipal solid waste.

The landfill area occupies the central portion of the Canada de La Pila, a narrow

canyon cut into the south flank of the Santa Ynez Mountains. Canada de la Pila

Creek flows directly into the Pacific Ocean, about 0.4 mile south of the landfill.

Elevations range from 120 feet above msl in the lower canyon area at the surface

discharge point to about 1150 feet at the watershed divide. Canada de La Pila is an

ephemeral creek and drains a watershed of about 468 acres. Of this, about 200 acres

lie upstream from the landfill along the main canyon.

The Technical Report, prepared by the County of Santa Barbara, Department of

Public Works, Solid Waste & Utilities Division, defines four laterally contiguous

segments of the Pila Creek drainage basin, based upon physiographical

characteristics and land use practices which are listed as follows:

C

The relatively undisturbed headwaters area;

C

The upper canyon area;

C

The landfill area;

C

The lower canyon area.

The landfill area includes the majority of the watershed area that has been

disturbed by site development activities. The landfill itself occupies approximately 78

acres.

According to the Santa Barbara County Flood Control Districts 1993 Precipitation

Report, the mean annual rainfall at the Tajiguas rain gaging station is 17.75 inches,